1. Field of the Invention
The present invention relates to drainage system grate assemblies. More particularly, the present invention relates to a drainage system grate assembly including a drainage system grate that can be secured over a drainage system without deforming the grate or causing a tripping hazard.
2. Description of the Prior Art
Drainage system grates are typically comprised of several tread bars and two or more crossbars that drop into frames to cover drainage systems. The frames are typically secured over or within a drainage system, while it is being constructed. The frames not only support the grates, but also provide a convenient platform to which the grates may be secured.
Drainage system grates are typically secured to their frames by grate locking assemblies to prevent theft by vandals or thieves and to ensure that the grates don't become unseated by heavy use. Stolen or unseated grates are hazardous, because a removed or unseated grate cannot prevent a person or a vehicle from falling into a drainage system.
Common grate locking assemblies typically include a grate bar affixed either above or below a few tread bars of a grate. A bolt is used to secure the grate bar to a locking bar, which is located within the drainage system and contacts the grate's frame to prevent the grate from being removed or unseated.
There are two main problems with these assemblies. One is that the grate bar must be added to an otherwise ready-to-install grate. This complicates the installation and can result in an aesthetically unappealing grate.
Another problem is that the grate bar is typically only affixed to some tread bars. This stresses those tread bars and not others. The stressed tread bars can bend and cause an uneven surface. The uneven surface is aesthetically unappealing and can present a tripping hazard.
Another common grate locking assembly uses a recessed area in two adjacent tread bars of a grate. The recessed area includes a hole through which a bolt penetrates, such that a head of the bolt rests in the recessed area. The bolt is attached to a locking bar below the grate allowing the locking bar to be rotated, such that ends of the locking bar seat within grooves in a frame. The grooves prevent the locking bar and the grate from being removed or unseated. A disadvantage of this construction is that only two tread bars are stressed, which can cause an uneven surface as discussed above.
Accordingly, there is a need for an improved drainage system grate assembly that overcomes the limitations of the prior art.